1. Technical Field
The present invention relates to a system, device, terminal unit, program and method for managing device identifiers, and more particularly to a device identification information managing system, network device, device managing terminal unit, device and terminal-unit programs and device identification information managing method which are suited for handling device identifiers with security.
2. Related Art
Where a service-providing server provides a network service such as a content distribution service to network devices, the service-providing server previously stores device identifiers based on each of the network devices. Prior to providing the network service, the service-providing server confirms the device identifiers with the network devices and determines eligibility for enjoying a network service provided during communication.
Conventionally, the device identifier managing methods include, first, a method that the user inputs a device identifier of the network device to the service-providing server so that the inputted device identifier can be registered. Second, there is also a method that, when the network device accesses the service-providing server, the service-providing server automatically recognizes a device identifier of the network device to thereby register the recognized device identifier. Third, there is a method that, when the network device accesses the service-providing server, the network device provides its own device identifier to the service-providing server in response to a provision request from the service-providing server, thereby registering the device identifier provided.
Furthermore, JP-A-2000-151704 also discloses a method of managing device identifiers. In this document, the service-providing server occasionally issues device identifiers to the accessing network devices thus providing network services made specific based on each of the network devices.
In such a network system, device identifiers are problematic in terms of security. Security is meant to prevent a device identifier from being stolen by a third person and to guarantee a device identifier as a registration based on the user's intention.
However, both the first and third managing methods are to utilize the device identifiers previously assigned to the network devices. Consequently, should the device identifier be known to a third person, the device identifier is possibly stolen by a third person and the device identifier is possibly registered without relying upon a user's intention.
Meanwhile, the invention described in JP-A-2000-151704 makes use of the device identifier issued from the service-providing server. When the device identifier is known to a third person, the device identifier is possibly registered without relying upon a user's intention.
Therefore, the present invention has been made in view of such unsolved problems involved in the prior art, and it is an object to provide a device identification information managing system, network device, device managing terminal unit, device and terminal-unit programs and device identification information managing method which are suited for handling device identifiers with security.